1. Field of the Invention
The invention relates generally to a rearview mirror assembly for a motor vehicle and more particularly to a twin-arm rearview mirror assembly having modular bearings between the arms and a mirror support bracket. In another embodiment, the mirror support bracket is provided with integral bearings. In yet another embodiment, a spring-biased friction wedge assembly controls the movement of the mirror support bracket relative to the arms.
2. Description of the Related Art
Motor vehicles typically include at least one external rearview mirror system for providing the operator with a rearward view. The mirror system typically comprises a base attached to the motor vehicle, a reflective element assembly comprising a mirror and a supporting bracket, and an arm assembly interconnecting the reflective element assembly and the base. With large mirrors, such as those found on trucks, the arm assembly will frequently comprise a twin-arm assembly.
The reflective element assembly can be adapted for selective extension away from, or retraction toward, the vehicle to adjust the rearward field of view. This extension and retraction can be accomplished manually by pushing or pulling the reflective element assembly to move the supporting bracket along the twin arms, or by a remotely controlled, motorized powerextend mechanism mounted to the base or the arm assembly and adapted to move the mirror bracket along the arms.
Typically, different mirror brackets will be utilized depending upon whether the mirror system is manually extendable or powerextended. The manually extended mirror system will typically utilize a supporting bracket which comprises a frictional bearing assembly which will enable the bracket to be moved along the twin arms but remain in a selected position. The powerextend mirror system will typically utilize a different support bracket comprising a roller bearing assembly to enable the powerextend mechanism to easily move the support bracket along the twin arms. The support bracket will be held in the selected position by the power extend mechanism.
It may be desirable to select an extension assembly which is different than that installed by the manufacturer. Thus, the owner of the vehicle may at some point desire powerextend functionality for a mirror system which was originally installed for manual extension. While this selectivity can be currently accommodated, it typically will involve either replacement of the entire mirror system, or disassembly of the mirror system and replacement of the support bracket. Moreover, if one bearing must be replaced due to wear or damage, regardless of the type of extension assembly involved, it will be necessary to replace the entire support bracket. Either situation will involve the expenditure of time, the removal of the vehicle from service, and cost. Finally, it may be necessary to modify the performance characteristics of the bearing assembly to accommodate changes in the fit and performance of the bearings due to wear, temperature, driving conditions, and the like. Conventional brackets do not readily accommodate such modifications.